See-through layered body, transparent screen comprising same, and image projection device comprising same

ABSTRACT

[Solving means] A see-through layered body according to the present invention comprises an intermediate resin film, two transparent substrates holding the intermediate resin film, wherein the intermediate resin film comprises a resin and from 0.0001 to 15% by mass of microparticles, having an average diameter of from 1 nm to 100 μm, and the center plane average roughness SRa of outermost surfaces on both sides of the layered body is from 0.05 to 5.5 nm.

TECHNICAL FIELD

The present invention relates to a see-through layered body suitablyused for a projection type image display transparent screen. Also, thepresent invention relates to a transparent screen comprising saidsee-through layered body and an image projection device comprising thesame.

BACKGROUND ART

Conventionally, a layered body of a combined glass type has been usedfor a transparent member having durability. The combined glass typelayered body is widely used as window glasses for vehicles such as cars,aircrafts and buildings since it is safe in that even though it isdamaged by external impact, the glass debris resist shattering. For suchcombined glass type layered body, one is used which comprises anintermediate film for the combined glass in between at least one pair ofglass. For the intermediate film for the combined glass, for example, apolyvinyl butyral intermediate film and an ethylene-vinyl acetatecopolymer intermediate film are generally known, and a vinyl chlorideresin intermediate film is also considered.

On one hand, there is a growing demand for displaying by projection, carnavigation on window glass of vehicles such as cars and displaying byprojection, merchandise information, advertisement, or the like on ashop window of a department store, or the like, or on a transparentpartition of an event venue, or the like while maintaining thetransparency thereof. However, no projector screens of a combined glasstype existed, capable of visualizing the image which has been projectedby a projector, while maintaining the safety and transparency as acombined glass type layered body.

However, since a conventional projector screen has a low transparency,there is a technical problem that such projector screen cannot beapplied to a transparent partition, or the like. Therefore, variousproposals have been made as below. There is proposed a screen having aconcave portion on the surface as a projector screen (see PatentDocument 1). A double face image film screen is proposed, comprising atransparent material of any one kind selected from the group ofpolyester, acryl, and polycarbonate; and a light refractive material ofsilica, contained in or coated on such transparent material, andcharacterized in removing a hot spot (see Patent Document 2). Atransmission type screen layered body is proposed, which is capable ofeasily attaching a transmission type screen when attaching thereof bywater to an attached substrate, such as a glass or a plastic board, andcapable of peeling off a light diffusion layer from the attachedsubstrate without any remainings thereof (see Patent Document 3). Atransmission type screen is proposed, wherein a Fresnel lens sheet/alenticular lens sheet/a light diffusion sheet are arranged in thisorder, wherein the light diffusion sheet is a combined glass having anintermediate resin film layer between two glass board-form bodies andthe haze is from 15 to 80% (see Patent Document 4). A transmission typescreen is proposed, comprising a transparent thin film layer comprisingdiamond microparticles with a median diameter of from 0.01 to 1 μmobtained by oxidation treatment of nanodiamonds having a graphite phaseobtained from exposure method (see Patent Document 5). A transparentlight diffusion body is proposed, containing a thin film (from 0.2 to400 μm), which nanoparticles of a high refractive index are dispersed ina dispersion medium to obtain a highly transparent transmission typescreen (see Patent Document 6).

RELATED ART DOCUMENTS Patent Documents

Patent Document 1 Japanese Unexamined Patent Application Publication No.2006-146019

Patent Document 2 Japanese Unexamined Patent Application Publication No.2006-503334 Patent Document 3 Japanese Unexamined Patent

Application Publication No. 2014-137539

Patent Document 4 Japanese Unexamined Patent Application Publication No.2007-057906

Patent Document 5 Japanese Unexamined Patent Application Publication No.2011-113068

Patent Document 6 Japanese Unexamined Patent Application Publication No.2014-153708

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

However, the present inventors found the following technical problems inPatent Documents 1 to 6. When the screen as described in Patent Document1 is applied to a shop window or a transparent partition of an eventvenue or the like, there is a technical problem that since the concaveportion wears out along with usage, it is poor in image clarity andtransparency, and that it is poor in durability, incapable ofmaintaining its property for a long period. The film screen as describedin Patent Document 2 is clouded in order to remove the hot spot and hasa technical problem that it has a low light transmittance, and poorimage clarity and transparency. Also, the film screen as described inPatent Document 2 has a technical problem that it is poor in durabilitysince a transparent material of any one kind selected from the group ofpolyester, acryl, and polycarbonate is used. The transmission typescreen layered body as described in Patent Document 3 has a technicalproblem that it is poor in image clarity and transparency since itcomprises a sticking layer planned to be stuck on a substrate such asglass. The transmission type screen lens sheet as described in PatentDocument 4 has a technical problem that it is poor in image clarity andtransparency since a lens sheet it disposed on a combined glass. Thenanodiamond particles used for the transparent screen as described inPatent Document 5 require many treatment steps and thus there is atechnical problem of poor production efficiency and production cost. Inparagraph [0113] of Patent Document 5, a transmission screen of acombined glass type is described; however the center plane averageroughness SRa of the glass substrate is not considered, and therefore, atransmission type screen having sufficient image clarity andtransparency cannot be obtained. Since the light scattering intensity ofthe high refractive particles is too large in the transparent lightdiffusion body as described in Patent Document 6, it has a technicalproblem that a screen having high image clarity and transparency isdifficult to be made.

Means for Solving the Problems

The present invention has been made in view of the above describedtechnical problems, and an object of the present invention is to providea see-through layered body which allows obtaining a projection typeimage display transparent screen with a wide viewing angle, andexcellent image clarity and transparency. Additionally, the object ofpresent invention is to provide a transparent screen comprising saidsee-through layered body, or an image projection device comprising saidsee-through layered body and a projection device.

In order to solve the above described technical problems, the presentinventors intensively studied to find that, in a see-through layeredbody (a combined glass type layered body) comprising an intermediateresin film and two transparent substrates holding the intermediate resinfilm, the above described technical problems can be solved when acertain amount of microparticles of a certain average diameter iscontained in the intermediate resin film and the center plane averageroughness SRa of the transparent substrate which is to be the outermostsurface of the layered body, is adjusted within a certain range.

That is, according to one aspect of the present invention, there isprovided a see-through layered body comprising an intermediate resinfilm and two transparent substrates holding said intermediate resinfilm, wherein

said intermediate resin film comprises a resin and from 0.0001 to 15% bymass of microparticles based on said resin, having an average diameterof from 1 nm to 100 μm; and

the center plane average roughness SRa of outermost surfaces on bothsides of said layered body is from 0.05 to 5.5 nm.

According to one aspect of the present invention, the microparticles arepreferably selected from the group consisting of zirconium oxide,titanium oxide, aluminum oxide, magnesium oxide, cerium oxide, bariumtitanate, barium sulfate, calcium carbonate, silica, aluminum, silver,platinum, gold, titanium, nickel, tin, indium, diamond, tin-cobaltalloy, zinc sulfide, metal-coated mica, metal-coated glass, acrylicbeads, and styrene beads.

According to one aspect of the present invention, preferably, themicroparticles have a content of from 0.001 to 2% by mass based on theresin and an average diameter of from 10 nm to 5 μm.

According to one aspect of the present invention, the total lighttransmittance of the layered body is preferably 65% or higher.

According to one aspect of the present invention, the haze value of thelayered body is preferably 35% or less.

According to one aspect of the present invention, the image clarity ofthe layered body is preferably 70% or higher.

According to one aspect of the present invention, the thickness of thelayered body is preferably from 10 μm to 100 mm.

According to one aspect of the present invention, the layered bodypreferably further comprises a transparent substrate.

In another aspect of the present invention, there is provided asee-through intermediate resin film used for the above describedsee-through layered body, wherein the image clarity of said intermediateresin film is 50% or higher.

In another aspect of the present invention, there is provided a memberfor a vehicle, comprising the above described see-through layered body.

In another aspect of the present invention, there is provided a memberfor a house, comprising the above described see-through layered body.

In another aspect of the present invention, there is provided areflection type transparent screen, comprising the above describedsee-through layered body.

In another aspect of the present invention, there is provided atransmission type transparent screen, comprising the above describedsee-through layered body.

In another aspect of the present invention, there is provided an imageprojection device comprising the above described see-through layeredbody and a projection device.

Effects of the Invention

The see-through layered body according to the present invention iscapable of providing a projection type image display transparent screenwith a wide viewing angle, and excellent image clarity and transparency.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional schematic diagram in the thickness directionof one embodiment of a see-through layered body according to the presentinvention.

FIG. 2 is a schematic diagram showing of one embodiment of a transparentscreen and an image projection device according to the presentinvention.

MODE FOR CARRYING OUT THE INVENTION

<See-Through Layered Body>

A see-through layered body according to the present invention comprisesan intermediate resin film and two transparent substrates holding theintermediate resin film. Such layered body can be suitably used as atransparent screen and can provide a clear image on the layered bodywithout compromising the image clarity and transparency. Theintermediate resin film having a light diffusion function is held by twotransparent substrates and is not exposed to the external. Therefore, itis less affected by the external which results in excellent durabilityof the layered body. Additionally, such layered body may furthercomprise other layers such as a reflection protection layer, as long asthe image clarity and transparency are not compromised.

FIG. 1 is a cross-sectional schematic diagram in the thicknessdirection, illustrating one embodiment of a see-through layered bodyaccording to the present invention. The see-through layered body 10comprises an intermediate resin film 12, in which microparticles 11 aredispersed in the resin, and two transparent substrates 13 holding theintermediate resin film 12.

The see-through layered body according to the present invention can beused directly as a transparent screen. Since the transmission visibilityof the transparent screen is required not to be compromised, the layeredbody preferably has a high transmittance of visible light, and highimage clarity and transparency. In the present invention, the term“transparent” means transparent in the degree that a transmissionvisibility depending on the applications is attained and also includesbeing translucent.

The total light transmittance of the layered body is preferably 65% orhigher, more preferably 70% or higher, still preferably 80% or higher,and still more preferably 85% or higher. The haze value of the layeredbody is preferably 35% or less, more preferably from 1 to 25%, morepreferably from 1.5 to 20%, still more preferably from 2 to 15%, andespecially preferably from 2.5 to 10%. When the total lighttransmittance and the haze value of the layered body are within theabove-mentioned ranges, the transparency will be high and thetransmission visibility can be more improved. In the present invention,the total light transmittance and the haze value of the layered body canbe measured in accordance with JIS-K-7361 and JIS-K-7136.

The image clarity of the layered body is preferably 70% or higher, morepreferably 75% or higher, still preferably 80% or higher, still morepreferably 85% or higher, and especially preferably 90% or higher. Whenthe image clarity of the layered body is within the above range, thetransmitted image to be seen will be extremely clear. In the presentinvention, the image clarity is a value of image definition (%) whenmeasured with an optical comb having a width of 0.125 mm in accordancewith JIS K7374.

In view of durability, application, productivity, handling, andtransportation, the thickness of the layered body is preferably from 10μm to 100 mm (100000 μm), more preferably from 50 μm to 50 mm (50000μm), and still preferably from 100 μm to 10 mm (10000 μm). In thepresent invention, “the see-through layered body” contains moldings ofvarious types such as films, sheets, or plates (board-like moldings).

(Intermediate Resin Film)

The intermediate resin film can be seen through and comprises a resinand microparticles dispersed therein. When the layered body is used as atransparent screen, the intermediate resin film having a light diffusionfunction sufficiently diffuses anisotropically a projected light emittedfrom the projection device, which will enable to satisfy bothvisibilities of a diffused light and a transmitted light.

The thickness of the intermediate resin film is preferably from 5 μm to1 mm (1000 μm), more preferably from 10 μm to 800 μm, still preferablyfrom 20 μm to 500 μm, and still more preferably from 50 μm to 300 μm.When the thickness of the intermediate resin film is within the abovedescribed ranges, both the visibilities of the diffused light and thetransmitted light can be satisfied by sufficiently diffusinganisotropically the projected light emitted from the projection devicewhile ensuring the transparency of the intermediate resin film.

(Resin)

As a resin forming the intermediate resin film, a highly transparentresin is preferably used in order to obtain a see-through layered body.For a highly transparent resin, a thermoplastic resin such as an acrylicresin, an acrylic urethane resin, a polyester acrylate resin, apolyurethane acrylate resin, an epoxy acrylate resin, a polyester resin,a polyolefin resin, a urethane resin, an epoxy resin, a polycarbonateresin, a cellulose resin, an acetal resin, a vinyl resin, a polystyreneresin, a polyamide resin, a polyimide resin, a melamine resin, a phenolresin, a silicone resin, a polyarylate resin, a polyvinyl alcohol resin,a polyvinyl chloride resin, a poly sulfone resin, and a fluorocarbonresin; a thermoset resin; an ionizing radiation-curable resin; or thelike can be used. Among these, a thermoplastic resin is preferably usedin view of formability of the intermediate resin film but withoutspecific limitation. As thermoplastic resins, preferably, an acrylicresin, a polyester resin, a polyolefin resin, a vinyl resin, apolycarbonate resin, and a polystyrene resin are used, and morepreferably, a polymethyl methacrylate resin, a polyethyleneterephthalate resin, a polyethylene naphthalate resin, a polypropyleneresin, a cycloolefin polymer resin, a cellulose acetate propionateresin, a polyvinyl butyral resin, a polycarbonate resin, and apolystyrene resin are used. These resins may be used singly, or incombination of two or more kinds thereof. The ionizing radiation-curableresin includes an acrylic resin, a urethane resin, an acrylic urethaneresin, an epoxy resin, and a silicone resin. Among these, those havingan acrylate functional group, for example, those containing a relativelyhigh amount of a monofunctional monomer such as ethyl (meth)acrylate,ethylhexyl (meth)acrylate, styrene, methyl styrene, N-vinylpyrrolidoneand a polyfunctional monomer, such as polymethylolpropanetri(meth)acrylate, hexane diol (meth)acrylate, tripropylene glycoldi(meth)acrylate, diethylene glycol di(meth)acrylate, pentaerythritoltri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,6-hexane dioldi(meth)acrylate, neopentyl glycol di(meth)acrylate as an oligomer or aprepolymer of a polyester resin, a polyether resin, an acrylic resin, anepoxy resin, a urethane resin, an alkyd resin, a spiroacetal resin, apolybutadiene resin, a polythiol polyene resin, a (meth)acrylate of apolyfunctional compound such as a polyalcohol and a reactivity diluenthaving a relatively low molecular weight are preferable. The ionizingradiation-curable resin may be obtained by mixing a thermoplastic resinand a solvent. The thermoset resin includes a phenol resin, an epoxyresin, a silicone resin, a melamine resin, a urethane resin, and a urearesin. Among these, an epoxy resin and a silicone resin are preferable.

(Microparticles)

As microparticles forming the intermediate resin film, an inorganic oran organic matter that can be atomized in a nano or a micron size may besuitably used. The shape of the microparticles is not particularlylimited and those of sphere form, flat shape form, cube, cuboid, flakeform, and amorphous form can be used. The average diameter of themicroparticles is from 0.1 nm to 100 μm, preferably from 1 nm to 50 μm,still preferably from 5 nm to 20 μm, still more preferably from 10 nm to10 μm, and especially preferably from 50 nm to 5 μm. When themicroparticles are in flake form, the average aspect ratio (=averagediameter/average thickness of the flake form microparticles) ispreferably from 3 to 800, more preferably from 4 to 700, stillpreferably from 5 to 600, and still more preferably from 10 to 500. Whenthe average diameter and the average aspect ratio are within the abovedescribed ranges, and the layered body is used for the transparentscreen, a sufficient scattering effect of the projection light can beobtained without compromising the transmission visibility, thus a clearimage can be projected. In the present invention, the average diameterof the microparticles was measured using a laser diffraction particlesize distribution measuring device (Part No.: SALD-2300; manufactured byShimadzu Corporation). In addition, the average aspect ratio of themicroparticles was calculated from an SEM (Trade Name: SU-1500;manufactured by Hitachi High Technologies Corporation) image.

As for the microparticles, those by atomizing inorganic matters such aszirconium oxide, titanium oxide, aluminum oxide, magnesium oxide, ceriumoxide, barium titanate, calcium carbonate, silica, and diamond, those byatomizing brilliant materials of inorganic matters such as aluminum,silver, platinum, gold, titanium, nickel, tin, indium, tin-cobalt alloy,zinc sulfide, metal-coated mica, and metal-coated glass, and those byatomizing organic matters such as acrylic resin beads and styrene resinbeads may be used. One kind of these microparticles may be usedsingularly or two kinds may be combined and used. Those commerciallyavailable may be used for these microparticles.

The content of microparticles in the intermediate resin film is from0.0001 to 15% by mass, preferably from 0.001 to 3% by mass, morepreferably from 0.0015 to 2% by mass, still preferably from 0.002 to 1%by mass, still more preferably from 0.003 to 0.5% by mass, andespecially preferably from 0.004 to 0.2% by mass, based on the resin.When the content of the microparticles in the intermediate resin film iswithin the above range, both the visibilities of diffused light andtransmitted light are satisfied by sufficiently diffusinganisotropically the projected light emitted from the projection devicewhile ensuring the transparency of in the intermediate resin film.

(Additives)

Conventionally known additives may be added to the intermediate resinfilm as long as the transmission visibility or the desired opticalperformance of the layered body is not compromised. Examples of theadditives include an antioxidant, a lubricant, an ultraviolet absorber,a dispersing agent, a dye, a compatibilizer, a nucleating agent, and astabilizer.

(Transparent Substrate)

The two transparent substrates constructing the layered body support theintermediate resin film and are positioned at the surface side of thelayered body. The center plane average roughness SRa of the outermostsurfaces on both sides of the layered body (when the transparentsubstrate is the outermost surface, then the face of the outermostsurface side of the transparent substrate) is from 0.05 to 5.5 nm,preferably from 0.05 to 5.0 nm, more preferably from 0.05 to 4.5 nm,still preferably from 0.05 to 2.5 nm, and still more preferably from0.05 to 1.0 nm. When the transparent screen is used with the centerplane average roughness SRa of the outermost surfaces on both sides ofthe layered body set within the above described range, high imageclarity can be achieved since the surface is smooth. The center planeaverage roughness SRa can be measured by using a surface micro figuremeasuring device, for example, Part No. SURFCORDER ET 4000A,manufactured by Kosaka Laboratory Ltd. In the present invention, asmooth surface can be achieved, by holding the intermediate resin filmwith transparent substrates having an extremely smooth surface, which isdifficult to be obtained when the intermediate resin film such as aresin molding or an injection molding board is directly used as thetransparent screen.

Other than the two transparent substrates holding the intermediate resinfilm, the layered body may further comprise a transparent substratethrough an adhesive layer on the transparent substrate, if necessary. Inthe present invention, a layered body further comprising a transparentsubstrate (a multilayered combined glass type layered body) may beappropriately used, in view of durability, application, productivity,handling, and transportation.

The kind of transparent substrate is not particularly limited butpreferably, glass, a polycarbonate based resin or a polyester basedresin, a resin board or the like, consisting of a transparent resin suchas an acrylic based resin is used, in view of durability, application,productivity, handling, and transportation.

In view of durability, application, productivity, handling, andtransportation, the thickness of the transparent substrate is preferablyfrom 5 μm to 50 mm (50000 μm), preferably from 50 μm to 20 mm (20000μm), and still preferably from 50 μm to 10 mm (10000 μm).

(Other Resin Films)

The layered body may further comprise other films in between theintermediate resin film and the two transparent substrates holding theintermediate resin film. For example, the layer construction of thelayered body can be of a transparent substrate/other resin film/anintermediate resin film/other resin film/a transparent substrate. Theother resin film can serve a function as an adhesive layer or a stickinglayer for improving the adhesion between the transparent substrates andthe intermediate resin film. For the resins forming the other resinfilms, for example, a polyvinyl butyral resin or an ethylene-vinylacetate copolymer resin may be suitably used. Similar resins to thoseforming the intermediate resin film as mentioned above may also be used.The kind of resins for the other resin films may be the same as, or maybe different from the kind of resin of the intermediate resin film.

(Reflection Protection Layer)

A reflection protection layer is a layer for preventing a reflection ora reflection of an external light on the outermost surface of thelayered body. The reflection protection layer may be layered on thesurface side of the layered body (the viewer side), or may be layered onboth faces. Especially when such layered body is used as a transparentscreen, the reflection protection layer is preferably layered on theviewer side. The reflection protection layer is preferably formed byusing a resin which does not compromise the transmission visibility or adesired optical property of the layered body. For such a resin, forexample, a resin cured by an ultraviolet light/electron beam, i.e., anionizing radiation-curable resin, those obtained by mixing athermoplastic resin and a solvent to an ionizing radiation-curableresin, and a thermoset resin can be used. Among these, an ionizingradiation-curable resin is particularly preferable.

A method for forming the reflection protection layer is not particularlylimited, and a dry coating method such as pasting of a coating film, ordirect deposition or sputtering on a film substrate; and a wet coatingtreatment method such as gravure coating, microgravure coating, barcoating, slide die coating, slot-die coating, and dip coating may beused.

<Method for Manufacturing Layered Body>

The method for manufacturing a layered body according to the presentinvention comprises a process for forming an intermediate resin layerand a process for holding the intermediate resin film by two transparentsubstrates. In the process for forming the intermediate resin film, theintermediate resin film may be molded and processed according to knownmethods such as extrusion molding comprising kneading and filmmanufacturing process, injection molding, calendering molding, blowmolding, compression molding, and casting. In view of the wide range ofthe film thickness that can be manufactured, extrusion molding methodcan be suitably used. Also, in view of formability of the thick filmsheet, injection molding method can be suitably used. In the following,each process of the manufacturing method will be described in details.

(Kneading Process)

A kneading process is a process where, using a kneading extruder, theabove described resin and microparticles are kneaded to obtain a resincomposition. For the kneading extruder, there are a single- and atwin-screw kneading extruder, and either can be used. When a twin-screwkneading extruder is used, preferably, the resin and the microparticlesas described above are kneaded while applying a shear stress, preferablyfrom 3 to 1,800 KPa, more preferably from 6 to 1,400 KPa on average overthe whole length of a screw of the twin-screw kneading extruder toobtain a resin composition. When the shear stress is within the abovedescribed range, the microparticles can be sufficiently dispersed in theresin. In particular, when the shear stress is 3 KPa or higher, thedispersion homogeneity of the microparticles can be more improved, andwhen the shear stress is 1,800 KPa or less, degradation of the resin isprevented, thereby preventing contamination of an air bubble in theintermediate resin film. The shear stress can be set in a desired rangeby regulating the twin-screw kneading extruder. In the presentinvention, a resin (master batch) to which microparticles are added inadvance and a resin to which microparticles are not added may be mixedtogether to be kneaded by a twin-screw kneading extruder, therebyobtaining a resin composition. The above description is one example of akneading process, and a resin (mater batch) to which microparticles areadded in advance may be prepared by a single-screw kneading extruder, ora master batch may be prepared by using a commonly known dispersingagent.

To the resin composition, other than the resin and the microparticles,conventionally known additives may be added as long as the transmissionvisibility or a desired optical performance of the layered body is notcompromised. Examples of the additives include an antioxidant, alubricant, an ultraviolet absorber, a dispersing agent, a dye, acompatibilizer, a nucleating agent, and a stabilizer. The resin and themicroparticles are as described above.

A twin-screw kneading extruder used in the kneading process comprises acylinder and two screws therein and is configured by combining screwelements. For the screw, a flight screw at least including a conveyingelement and a kneading element is suitably used. The kneading elementpreferably includes at least one selected from the group consisting of akneading element, a mixing element, and a rotary element. By using suchflight screw including a kneading element, the microparticles can besufficiently dispersed in the resin while applying a desired shearstress.

(Film Manufacturing Process)

A film manufacturing process is a process in which a film is made of theresin composition obtained in the kneading process. A film manufacturingmethod is not particularly limited, and a film consisted of a resincomposition can be made by a conventionally known method. For example,the resin composition obtained in the kneading process is provided to amelt extruder heated to a temperature (from Tm to Tm+70° C.) of themelting point or higher to melt the resin composition. For the meltextruder, a single-screw extruder, a twin-screw extruder, a ventextruder, or a tandem extruder can be used depending on the purposes.

Subsequently, the molten resin composition is, for example, extrudedinto a sheet form by a die such as a T-die, and the extruded sheet-formarticle is rapidly quenched and solidified by a revolving cooling drumor the like, thereby forming a film. When the film manufacturing processis performed continuously with the above described kneading process, theresin composition obtained in the kneading process in a molten state maybe directly extruded to a sheet form from a die to form a film-shapedintermediate resin film.

The intermediate resin film in a film shape obtained in the filmmanufacturing process can be further uniaxially or biaxially stretchedby a conventionally known method. Stretching of the above describedintermediate resin film can improve its strength.

(Holding Process)

The holding process is a process to hold the intermediate resin filmobtained as described above, by two transparent substrates. For example,the intermediate resin film is cut into a required size and put in to anylon bag equipped with a tube connected to a vacuum pump, in a statebeing held by the transparent substrates. The nylon bag is put into anautoclave and then heated at a temperature higher than the glasstransition temperature of the resin forming the intermediate resin film,with the inside of the nylon bag set to a vacuum state. A temporaryadhered layered body can be obtained by heating in vacuum. The temporaryadhered layered body is put into the autoclave again and heated at atemperature higher than the softening temperature of the resin formingthe intermediate resin film, with applying pressure. A completelyadhered layered body can be obtained after the temperature hasdecreased.

<Member for Vehicle>

A member for a vehicle according to the present invention comprises thesee-through layered body as described above. The member for a vehiclemay be constituted only by the above described see-through layered body,or may further comprise a reflection protection layer or the like. Themember for a vehicle includes a windshield or a side glass. When themember for a vehicle comprises the see-through layered body as describedabove, a clear image can be displayed on the member for a vehiclewithout providing a separate screen.

<Member for House>

A member for a house according to the present invention comprises thesee-through layered body as described above. The member for a house maybe consisted of only the above described see-through layered body, ormay further comprise a reflection protection layer or the like. Themember for a house includes a window glass for a house, a glass wall fora convenient store or a shop along the street. When the member for ahouse comprises the see-through layered body as described above, a clearimage can be displayed on the member for a house without providing aseparate screen.

<Transparent Screen>

The transparent screen according to the present invention comprises theabove described see-through layered body. The transparent screen may beconsisted of only the above described see-through layered body, or mayfurther comprise a reflection protection layer or the like.

The transparent screen may be a rear projection type screen (atransmission type screen) or a front projection type screen (areflection type screen). That is to say, in the image display devicecomprising the transparent screen according to the present invention,the position of a light source may be at the viewer side against thescreen or may be at the opposite side of the viewer.

<Image Projection Device>

The image projection device according to the present invention comprisesthe above described see-through layered body and a projection device.The projection device is not particularly limited, as long as it iscapable of projecting an image onto a screen, and for example,commercially available rear or front projectors can be used.

FIG. 2 is a schematic diagram illustrating one embodiment of thetransparent screen and the image projection device according to thepresent invention. For a transparent screen 21, the see-through layeredbody 10 as illustrated in FIG. 1 can be directly used. In case of a rearprojection type screen, the image projection device comprises thetransparent screen 21 and a projection device 23A, set at the oppositeside (rear side) of a viewer 22 against the transparent screen 21. Aprojection light 24A emitted from the projection device 23A enters fromthe rear side of the transparent screen 21 and diffuses anisotropicallyby the transparent screen 21, whereby the viewer 22 can visuallyrecognize a diffused light 25A. In case of a front projection typescreen, the image projection device comprises the transparent screen 21and a projection device 23B, set at the same side (front side) of theviewer 22 against the transparent screen 21. A projection light 24Bemitted from the projection device 23B enters from the front side of thetransparent screen 21 and diffuses anisotropically by the transparentscreen 21, whereby the viewer 22 can visually recognize a diffused light25B.

EXAMPLES

In the following, the present invention will be more specificallydescribed with reference to Examples and Comparative Examples, but thepresent invention should not be construed to be limited to the followingExamples.

The measuring methods of various physicalities and performanceevaluation in the Examples and the Comparative Examples are as follows.

(1) Average Diameter

Average diameter was measured by using a laser diffraction particle sizedistribution measuring device (Part No., SALD-2300; manufactured byShimadzu Corporation).

(2) Center Plane Average Roughness SRa

Center plane average roughness SRa was measured by using a surface microfigure measuring device (Part No. SURFCORDER ET 4000A; manufactured byKosaka Laboratory Ltd.).

(3) Total Light Transmittance

Total light transmittance was measured by using a turbidimeter (PartNo.: NDH-5000; manufactured by NIPPON DENSHOKU INDUSTRIES CO., LTD.) inaccordance with JIS K7361-1.

(4) Haze

Haze was measured by using a turbidimeter (Part No.: NDH-5000;manufactured by NIPPON DENSHOKU INDUSTRIES CO., LTD.) in accordance withJIS K7136.

(5) Image Clarity

Image clarity is a value of image definition (%) when measured by usingan image clarity measuring device (Part No.: ICM-IT; manufactured bySuga Test Instruments Co., Ltd.), with an optical comb having a width of0.125 mm in accordance with JIS K7374. The larger the value of thedefinition, the higher is the transmission image clarity.

(6) Transparency

Transparency of the layered bodies prepared below was visually evaluatedbased on the following criteria.

[Evaluation Criteria]

◯: Excellent transparency

x: Poor transparency

(7) Image Sharpness

An image was projected on the layered body made as a transparent screenas described below by using a mobile LED mini projector PP-D1S,manufactured by Onkyo Digital Solutions Corporation, from a position 50cm away in an angle of 15 degrees against a normal line direction. Then,after adjusting a focus knob of the projector to bring focus on thescreen surface, the image displayed on the screen was visually evaluatedfrom 2 places: 1 m frontward from the screen (the same side as theprojector against the screen; so-called a front projection); and 1 mbackward from the screen (the opposite side of the projector against thescreen; so-called a rear projection), under the following evaluationcriteria. Performance as a reflection type screen can be evaluated byobserving from the front of the screen and performance as a transmissiontype screen can be evaluated by observing from the back of the screen.

[Evaluation Criteria]

⊚: A significantly clear image was visualized

◯: A clear image was visualized

x: An image was not visualized

x: An image was not visualized

(8) Viewing Angle

Viewing angle was measured by using a goniophotometer (Part No.:GC5000L; manufactured by NIPPON DENSHOKU INDUSTRIES CO., LTD.). Anentering angle of a light source was set to 0 degree, and a transmittedlight intensity in the direction of 0 degree with nothing placed on themeasuring stage was 100. When a sample was measured, the transmittedlight intensity was measured by 1 degree from −85 degrees to +85 degreeswith the entering angle of the light source kept at 0 degree. Among themeasured range, the range having the transmitted light intensity of0.001 or higher was the viewing angle.

Example 1

(1) Manufacturing Process of an Intermediate Resin Film (KneadingProcess/Film Manufacturing Process)

100 parts by mass of polyvinyl butyral powder (Trade Name: Mowital B30H;manufactured by Kuraray Co., Ltd.) and 0.3 part by mass of zirconiumoxide powder (average diameter: 11 nm; manufactured by Kanto Denka KogyoCo., Ltd.) were mixed homogeneously. The mixed powders were introducedinto a hopper of a twin-screw kneading extruder (manufactured byTECHNOVEL CORPORATION) equipped with a T-die and were extruded at 180°C. to obtain an intermediate resin film in a thickness of 100 μm. Thecenter plane average roughness (SRa) in the range of 5 mm×5 mm of theintermediate resin film was measured and resulted to be 5.8 nm, and theimage clarity was 66%.

(2) Manufacturing Process of a Layered Body (Holding Process)

The obtained intermediate resin film was cut into 12 cm×12 cm andsubsequently held by two glass substrates (SRa: 0.45 nm; thickness: 2mm). Then, it was put into a nylon bag and heated for 2 hours at atemperature higher than the glass transition temperature of thepolyvinyl butyral (PVB) (80° C. in the present Example) in an autoclaveof a normal pressure, with the inside of the bag set to vacuum by avacuum pump. Then, the temporary adhered combined glass type layeredbody was removed from the bag and it was heated for 2 hours at atemperature higher than the softening temperature of the PVB resin (160°C.) in the autoclave of pressure at 8 kg/cm² to obtain a completelyadhered layered body.

(3) Evaluation of Transparent Screen

When the obtained layered body was directly used as a transparentscreen, the total light transmittance was 89%, the haze value was 14%,and the transparency was sufficient. The image clarity was 94% and thetransmitted image to be seen was extremely clear. Further, the imagesharpness was visually evaluated, whereby the image was clearlyvisualized by observing both from the front and the back. Especially, anextremely clear image was visualized by observing from the back. Theviewing angle measured by a goniophotometer was ±24 degrees, which wasfound to result in excellent viewing angle property.

Example 2

A layered body was manufactured in the same manner as Example 1, exceptthat two glass substrates (SRa: 0.06 nm; thickness: 2 mm) were used inthe (2) manufacturing process of the layered body.

When the obtained layered body was directly used as a transparentscreen, the total light transmittance was 89%, the haze value was 13%,and the transparency was sufficient. The image clarity was 96% and thetransmitted image to be seen was extremely clear. Further, the imagesharpness was visually evaluated, whereby the image was clearlyvisualized by observing both from the front and the back. Especially, anextremely clear image was visualized by observing from the back. Theviewing angle measured by a goniophotometer was ±23 degrees, which wasfound to result in excellent viewing angle property.

Example 3

A layered body was manufactured in the same manner as Example 1, exceptthat two glass substrates (SRa: 2.5 nm; thickness: 2 mm) were used inthe (2) manufacturing process of the layered body.

When the obtained layered body was directly used as a transparentscreen, the total light transmittance was 89%, the haze value was 14%,and the transparency was sufficient. The image clarity was 90% and thetransmitted image to be seen was extremely clear. Further, the imagesharpness was visually evaluated, whereby the image was clearlyvisualized by observing both from the front and the back. Especially, anextremely clear image was visualized by observing from the back. Theviewing angle measured by a goniophotometer was ±24 degrees, which wasfound to result in excellent viewing angle property.

Example 4

A layered body was manufactured in the same manner as Example 1, exceptthat two glass substrates (SRa: 4.5 nm; thickness: 2 mm) were used inthe (2) manufacturing process of the layered body.

When the obtained layered body was directly used as a transparentscreen, the total light transmittance was 89%, the haze value was 14%,and the transparency was sufficient. The image clarity was 81% and thetransmitted image to be seen was clear. Further, the image sharpness wasvisually evaluated, whereby the image was clearly visualized byobserving both from the front and the back. Especially, an extremelyclear image was visualized by observing from the back. The viewing anglemeasured by a goniophotometer was ±24 degrees, which was found to resultin excellent viewing angle property.

Example 5

An intermediate resin film was manufactured in the same manner asExample 1, except that 14 parts by mass of dry type silica particles(Trade Name: NHM-4N; hydrophobic; average diameter: 90 nm; manufacturedby Tokuyama Corporation) were added as microparticles and the thicknessof the intermediate resin film was changed to 50 μm in the (1)manufacturing process of the intermediate resin film. The center planeaverage roughness (SRa) in the range of 5 mm×5 mm of the intermediateresin film was measured and resulted to be 6.2 nm, and the image claritywas 55%. Subsequently, a layered body was manufactured in the samemanner as Example 1.

When the obtained layered body was directly used as a transparentscreen, the total light transmittance was 89%, the haze value was 31%,and the transparency was sufficient. The image clarity was 88% and thetransmitted image to be seen was clear. Further, the image sharpness wasvisually evaluated, whereby the image was clearly visualized byobserving both from the front and the back. Especially, an extremelyclear image was visualized by observing from the back. The viewing anglemeasured by a goniophotometer was ±31 degrees, which was found to resultin excellent viewing angle property.

Example 6

An intermediate resin film was manufactured in the same manner asExample 1, except that 0.008 part by mass of flake-form aluminummicroparticles (average diameter: 10 μm; aspect ratio: 300) havingbrilliance were added as microparticles in the (1) manufacturing processof the intermediate resin film. The center plane average roughness (SRa)in the range of 5 mm×5 mm of the intermediate resin film was measuredand resulted to be 5.4 nm, and the image clarity was 70%. Subsequently,a layered body was manufactured in the same manner as Example 1.

When the obtained layered body was directly used as a transparentscreen, the total light transmittance was 87%, the haze value was 4.3%,and the transparency was sufficient. The image clarity was 94% and thetransmitted image to be seen was clear. Further, the image sharpness wasvisually evaluated, whereby the image was clearly visualized byobserving both from the front and the back. Especially, an extremelyclear image was visualized by observing from the front. The viewingangle measured by a goniophotometer was ±15 degrees, which was found toresult in excellent viewing angle property.

Example 7

An intermediate resin film was manufactured in the same manner asExample 1, except that 0.04 part by mass of flake-form aluminummicroparticles (average diameter: 10 μm; aspect ratio: 300) havingbrilliance were added as microparticles in the (1) manufacturing processof the intermediate resin film. The center plane average roughness (SRa)in the range of 5 mm×5 mm of the intermediate resin film was measuredand resulted to be 5.6 nm, and the image clarity was 69%. Subsequently,a layered body was manufactured in the same manner as Example 1.

When the obtained layered body was directly used as a transparentscreen, the total light transmittance was 70%, the haze value was 17%,and the transparency was sufficient. The image clarity was 94% and thetransmitted image to be seen was clear. Further, the image sharpness wasvisually evaluated, whereby the image was extremely clearly visualizedby observing both from the front and the back. The viewing anglemeasured by a goniophotometer was ±25 degrees, which was found to resultin excellent viewing angle property.

Example 8

An intermediate resin film was manufactured in the same manner asExample 1, except that 0.15 part by mass of zirconium oxide powder(average diameter: 11 nm; manufactured by Kanto Denka Kogyo Co., Ltd.)and 0.008 part by mass of flake-form aluminum microparticles (averagediameter: 10 μm; aspect ratio: 300) having brilliance were added asmicroparticles in the (1) manufacturing process of the intermediateresin film. The center plane average roughness (SRa) in the range of 5mm×5 mm of the intermediate resin film was measured and resulted to be5.6 nm, and the image clarity was 68%. Subsequently, a layered body wasmanufactured in the same manner as Example 1.

When the obtained layered body was directly used as a transparentscreen, the total light transmittance was 86%, the haze value was 12%,and the transparency was sufficient. The image clarity was 94% and thetransmitted image to be seen was clear. Further, the image sharpness wasvisually evaluated, whereby the image was extremely clearly visualizedby observing both from the front and the back. The viewing anglemeasured by a goniophotometer was ±23 degrees, which was found to resultin excellent viewing angle property.

Example 9

An intermediate resin film was manufactured in the same manner asExample 1, except that 0.003 part by mass of flake-form aluminummicroparticles (average diameter: 1 μm; aspect ratio: 300) havingbrilliance were added as microparticles in the (1) manufacturing processof the intermediate resin film. The center plane average roughness (SRa)in the range of 5 mm×5 mm of the intermediate resin film was measuredand resulted to be 5.2 nm, and the image clarity was 72%. Subsequently,a layered body was manufactured in the same manner as Example 1.

When the obtained layered body was directly used as a transparentscreen, the total light transmittance was 89%, the haze value was 3.5%,and the transparency was sufficient. The image clarity was 94% and thetransmitted image to be seen was extremely clear. Further, the imagesharpness was visually evaluated, whereby the image was clearlyvisualized by observing both from the front and the back. Especially, anextremely clear image was visualized by observing from the front. Theviewing angle measured by a goniophotometer was ±14 degrees, which wasfound to result in excellent viewing angle property.

Example 10

(1) Manufacturing Process of an Intermediate Resin Film (KneadingProcess/Film Manufacturing Process)

An intermediate resin film was manufactured in the same manner asExample 1, except that a polyethylene terephthalate resin (Trade Name:IFG8L; manufactured by Bell Polyester Products, Inc.) was used insteadof a polyvinyl butyral resin, the added amount of the zirconium oxidepowder was changed to 0.1 part by mass, and the extrusion temperaturewas changed to 250° C. in the manufacturing process of the intermediateresin film. The center plane average roughness (SRa) in the range of 5mm×5 mm of the intermediate resin film was measured and resulted to be4.8 nm, and the image clarity was 77%.

(2) Manufacturing Process of a Layered Body (Holding Process)

Subsequently, PVB resin powder (Trade Name: Mowital B30H; manufacturedby Kuraray Co., Ltd.) was introduced into a hopper of a twin-screwkneading extruder (manufactured by TECHNOVEL CORPORATION) equipped witha T-die and were extruded at 180° C. to obtain another resin film (a PVBresin film) in a thickness of 100 μm. The obtained PVB resin film andthe intermediate resin film were cut into 12 cm×12 cm and a layered bodylayered in the order from a PVB resin film/an intermediate resin film/aPVB resin film was held by two glass substrates (SRa: 0.45 nm;thickness: 2 mm). Subsequently, it was put into a nylon bag and washeated for 2 hours at a temperature higher than the glass transitiontemperature of the PVB resin (80° C. in the present Example) in anautoclave of a normal pressure, with the inside of the bag set to vacuumby a vacuum pump. Then, the temporary adhered combined glass typelayered body was removed from the bag and heated for 2 hours at atemperature higher than the softening temperature of the PVB resin (160°C.) in the autoclave at a pressure of 8 kg/cm² to manufacture acompletely adhered layered body.

(3) Evaluation of a Transparent Screen

When the obtained layered body was directly used as a transparentscreen, the total light transmittance was 88%, the haze value was 6.9%,and the transparency was sufficient. The image clarity was 94% and thetransmitted image to be seen was extremely clear. Further, the imagesharpness was visually evaluated, whereby the image was clearlyvisualized by observing both from the front and the back. Especially, anextremely clear image was visualized by observing from the back. Theviewing angle measured by a goniophotometer was ±23 degrees, which wasfound to result in excellent viewing angle property.

Comparative Example 1

A layered body was manufactured by adhering the intermediate resin filmobtained from Example 1, to one surface of one glass substrate (SRa: 2.5nm; thickness: 2 mm) at room temperature of 25° C. by using an acrylicresin based adhesive in the (2) manufacturing process of the layeredbody.

When the obtained layered body was directly used as a transparentscreen, the total light transmittance was 89%, the haze value was 14%,and the transparency was sufficient. Further, the image sharpness wasvisually evaluated, whereby the image was clearly visualized byobserving both from the front and the back. The viewing angle measuredby a goniophotometer was ±24 degrees, which was found to result inexcellent viewing angle. However, the image clarity was 65%, and whenthe letters of the background were seen through the screen, they weredistorted and difficult to be read. Since the intermediate resin filmexisted at the outermost layer, the surface roughness SRa of one side ofthis screen was 5.8 nm. It was identified that the screen with the glasssubstrates holding the intermediate resin film, like Example 1, haveexcellent image clarity as the interface and the surface can be madesmooth; however the image clarity decreases with the externally attachedscreen since the surface is rough.

Comparative Example 2

100 parts by mass of a PET pellet (Trade Name: IP121B; manufactured byBell Polyester Products, Inc.) and 0.3 part by mass of zirconium oxidepowder (average diameter: 11 nm; manufactured by Kanto Denka Kogyo Co.,Ltd.) were mixed homogeneously in the (1) manufacturing process of theintermediate resin film. The mixed powders were introduced into a hopperof a twin-screw kneading extruder (manufactured by TECHNOVELCORPORATION) equipped with a T-die and were extruded at 270° C. toobtain an intermediate resin film in a thickness of 100 μm. The centerplane average roughness (SRa) in the range of 5 mm×5 mm of theintermediate resin film was measured and resulted to be 4.9 nm, and theimage clarity was 71%.

When the obtained intermediate resin film was directly used as atransparent screen, the total light transmittance was 89%, the hazevalue was 14%, and the transparency was sufficient. Further, the imagesharpness was visually evaluated, whereby the image was clearlyvisualized by observing both from the front and the back. The viewingangle measured by a goniophotometer was ±24 degrees, which was found toresult in excellent viewing angle property. However, the image claritywas 68%, and when the letters of the background were seen through thescreen, they were distorted and difficult to be read.

Comparative Example 3

100 parts by mass of a PMMA pellet (Trade Name: ACRYPET VH; manufacturedby Mitsubishi Rayon Co., Ltd.) and 0.01 part by mass of zirconium oxidepowder (average diameter: 11 nm; manufactured by Kanto Denka Kogyo Co.,Ltd.) were mixed homogeneously in the (1) manufacturing process of theintermediate resin film. The mixed powders were introduced into a hopperof an injection molding machine (manufactured by TECHNOVEL CORPORATION)equipped with a strand die and were extruded at 250° C. to obtain a PMMApellet, which the zirconium oxide microparticles are dispersed therein.The obtained pellet was injected with an injection molding machine(Trade Name: FNX-III; manufactured by Nissei Plastic Industrial Co.,Ltd.) at 270° C. to manufacture a board-form molding with a thickness of4 mm and the length and width of 12 cm. The surface roughness SRa of theobtained board-like molding (an acrylic board) was 5.2 nm, and the imageclarity was 66%.

When the obtained board-like molding was directly used as a transparentscreen, the total light transmittance was 88%, the haze value was 16%,and the transparency was sufficient. Further, the image sharpness wasvisually evaluated, whereby the image was clearly visualized byobserving from the back but the image was not clear by observing fromthe front. The viewing angle measured by a goniophotometer was ±25degrees, which was found to result in excellent viewing angle property.However, the image clarity was 66%, and when the letters of thebackground were seen through the screen, they were distorted anddifficult to be read.

Comparative Example 4

A layered body was manufactured in the same manner as Example 1, exceptthat two glass substrates (SRa: 6.3 nm; thickness: 2 mm) were used inthe (2) manufacturing process of the layered body.

When the obtained layered body was directly used as a transparentscreen, the total light transmittance was 88%, the haze value was 16%,and the transparency was sufficient. Further, the image sharpness wasvisually evaluated, whereby the image was clearly visualized byobserving both from the front and the back. The viewing angle measuredby a goniophotometer was ±25 degrees, which was found to result inexcellent viewing angle property. However, the image clarity was 65%,and when the letters of the background were seen through the screen,they were distorted and difficult to be read.

Comparative Example 5

An intermediate resin film was manufactured in the same manner asExample 1, except that 18 parts by mass of dry type silica particles(Trade Name: NHM-4N; hydrophobic; average diameter: 90 nm; manufacturedby Tokuyama Corporation) were added as microparticles, and the thicknessof the intermediate resin film was changed to 50 μm in the (1)manufacturing process of the intermediate resin film. Subsequently, alayered body was manufactured in the same manner as Example 1. Thecenter plane average roughness (SRa) in the range of 5 mm×5 mm of theintermediate resin film was measured and resulted to be 6.6 nm, and theimage clarity was 43%.

When the obtained layered body was directly used as a transparentscreen, the total light transmittance was 88% and the image clarity was85%. Further, the image sharpness was visually evaluated, whereby theimage was clearly visualized by observation from the back; however, whenobserving from the front, the fineness of the projector image was poor,resulting in an unclear projected image. The viewing angle measured by agoniophotometer was ±33 degrees, which was found to result in excellentviewing angle property. However, the haze value was 37%, thetransparency was poor, and since the screen was clouded, the letters ofthe background were unable to be read clearly.

Comparative Example 6

An intermediate resin film was manufactured in the same manner asExample 1, except that 0.3 part by mass of cross-linked acrylic resinbeads (Part No: Techno Polymer MBX-40; average diameter: 40 μm;manufactured by Sekisui Plastics Co., Ltd.) were added as microparticlesin the (1) manufacturing process of the intermediate resin film. Thecenter plane average roughness (SRa) in the range of 5 mm×5 mm of theintermediate resin film was measured and resulted to be 7.4 nm, and theimage clarity was 41%. Subsequently, a layered body was manufactured inthe same manner as Example 1.

When the obtained layered body was directly used as a transparentscreen, the total light transmittance was 87%, the haze value was 19%,and the image clarity was 81%. The viewing angle measured by agoniophotometer was ±20 degrees, which was found to result in excellentviewing angle property. However, when the image sharpness was visuallyevaluated, the fineness of the projector image was poor, observing bothfrom the front and the back, and the projected image was unclear. It wasnot applicable for a screen.

Details of the various physicalities and the results of performanceevaluation of the layered bodies and the transparent screensmanufactured in the Examples and the Comparative Examples are shown inTable 1.

TABLE 1 Intermediate resin film Average Concen- Layered body Transparentscreen Transparent diameter Aspect tration SRa of Total light Imagesubstrate Type of micro- ratio of micro- Thick- image outermost Thick-transmit- Haze image sharpness Viewing SRa of micro- particles of micro-particles SRa ness clarity surface ness tance value clarity Trans- FrontBack angle [nm] particles [nm] particles [mass %] [nm] [μm] [%] [nm][mm] [%] [%] [%] parency observation observation [degrees] Example 10.45 Zirconium 11 — 0.3 5.8 100 66 0.45 4.1 89 14 94 ◯ ◯ ⊚ ±24 oxideExample 2 0.06 Zirconium 11 — 0.3 5.8 100 66 0.06 4.1 89 13 96 ◯ ◯ ⊚ ±23oxide Example 3 2.5 Zirconium 11 — 0.3 5.8 100 66 2.5 4.1 89 14 90 ◯ ◯ ⊚±24 oxide Example 4 4.5 Zirconium 11 — 0.3 5.8 100 66 4.5 4.1 89 14 81 ◯◯ ⊚ ±24 oxide Example 5 0.45 Silica 90 — 14 6.2 50 55 0.45 4.05 89 31 88◯ ◯ ⊚ ±31 Example 5 0.45 Aluminum 10000 300 0.008 5.4 100 70 0.45 4.1 874.3 94 ◯ ⊚ ◯ ±15 Example 7 0.45 Aluminum 10000 300 0.04 5.6 100 69 0.454.1 70 17 94 ◯ ⊚ ⊚ ±25 Example 8 0.45 Zirconium 11 — 0.15 5.6 100 680.45 4.1 86 12 94 ◯ ⊚ ⊚ ±23 oxide Aluminum 10000 300 0.008 Example 90.45 Aluminum 1000 300 0.003 5.2 100 72 0.45 4.1 89 3.5 94 ◯ ⊚ ◯ ±14Example 10 0.1 Zirconium 11 — 0.1 4.8 100 77 0.45 4.2 88 6.9 94 ◯ ◯ ⊚±23 oxide Comparative 0.45 Zirconium 11 — 0.3 5.8 100 66 5.8 2.1 89 1465 ◯ ◯ ◯ ±24 Example 1 oxide Comparative — Zirconium 11 — 0.3 4.9 100 71— — 89 14 68 ◯ ◯ ◯ ±24 Example 2 oxide Comparative — Zirconium 11 — 0.015.2 4000 66 — — 88 16 66 ◯ Δ ◯ ±25 Example 3 oxide Comparative 6.3Zirconium 11 — 0.3 5.8 100 66 6.3 4.1 88 16 65 ◯ ◯ ◯ ±25 Example 4 oxideComparative 0.45 Silica 90 — 18 6.6 50 43 0.45 4.05 88 37 85 X Δ ⊚ ±33Example 5 Comparative 0.45 Cross-linked 40 — 0.3 7.4 100 41 0.45 4.1 8719 81 ◯ X X ±20 Example 6 acrylic resin

DESCRIPTION OF SYMBOLS

-   10 See-through layered body-   11 Microparticle-   12 Intermediate resin film-   13 Transparent substrate-   21 Transparent screen-   22 Viewer-   23A, 23B Projection device-   24A, 24B Projected light-   25A, 25B Diffused light

The invention claimed is:
 1. A transparent screen comprising asee-through layered body comprising an intermediate resin film and twotransparent substrates holding the intermediate resin film, wherein theintermediate resin film comprises a resin and from 0.0001 to 15% by massof microparticles based on the resin, having an average diameter of from1 nm to 100 μm, a center plane average roughness SRa of outermostsurfaces on both sides of the layered body is from 0.05 to 1.0 nm, andan image clarity of the layered body is 70% or higher when measured byusing an image clarity measuring device with an optical comb having awidth of 0.125 mm.
 2. The transparent screen according to claim 1,wherein the microparticles are selected from the group consisting ofzirconium oxide, titanium oxide, aluminum oxide, magnesium oxide, ceriumoxide, barium titanate, barium sulfate, calcium carbonate, silica,aluminum, silver, platinum, gold, titanium, nickel, tin, indium,diamond, tin-cobalt alloy, zinc sulfide, metal-coated mica, metal-coatedglass, acrylic beads and styrene beads.
 3. The transparent screenaccording to claim 1, wherein the microparticles have a content from0.001 to 2% by mass based on the resin and an average diameter of from10 nm to 5 μm.
 4. The transparent screen according to claim 1, wherein atotal light transmittance of the layered body is 65% or higher.
 5. Thetransparent screen according to claim 1, wherein a haze value of thelayered body is 35% or less.
 6. The transparent screen according toclaim 1, wherein a thickness of the layered body is from 10 μm to 100mm.
 7. The transparent screen according to claim 1, wherein the layeredbody further comprises a transparent substrate.
 8. The transparentscreen according to claim 1, wherein the transparent screen is areflection type transparent screen.
 9. The transparent screen accordingto claim 1, wherein the transparent screen is a transmission typetransparent screen.
 10. The transparent screen according to claim 1,wherein the microparticles are flake-form microparticles having anaverage aspect ratio of from 3 to
 800. 11. The transparent screenaccording to claim 1, wherein the microparticles have a content from0.0001 to 0.04% by mass based on the resin.